We were into truck campers in the '60s and '70s with a 8'/9.5' and a 10.5' TC.
Back then it was common for the TC to be bolted to the beds frame or tie downs/turnbuckles from the bed stake holes.
As one poster said looking through his windshield at the cab over it could moves several inches especially when fighting strong head winds or a passing semi truck. The camper would literally shake the truck. We installed Camper Dampers hyd shocks to cure this issue. It worked.
Camper Damper shocks was a name brand back then. I did a quick google and it didn't show anything so recon they don't make them anymore or they have changed names.